Eosinophil granule proteins in serum and urine of patients with helminth infections and atopic dermatitis

Urine eosinophil-derived neurotoxin: A potential marker of activity in select eosinophilic disorders

BACKGROUND

Biomarkers of eosinophilic disease activity, especially in the context of novel therapies that reduce blood eosinophil counts, are an unmet need. Absolute eosinophil count (AEC) does not accurately reflect tissue eosinophilia or eosinophil activation. Therefore, the aims of this study were to compare the reliability of plasma and urine eosinophil major basic protein 1, eosinophil cationic protein, eosinophil-derived neurotoxin (EDN), and eosinophil peroxidase measurement and to evaluate the usefulness of eosinophil granule protein (EGP) measurement for the assessment of disease activity in patients with eosinophil-associated diseases treated with mepolizumab, benralizumab, or dexpramipexole.

METHODS

Eosinophil granule protein concentrations were measured in serum, plasma, and urine from healthy volunteers and patients with hypereosinophilic syndrome (HES), eosinophilic granulomatosis with polyangiitis (EGPA), and eosinophilic asthma using a multiplex assay.

RESULTS

Urine EGP concentrations remained stable, whereas serum and plasma EGP concentrations increased significantly with delayed processing. Plasma (p) EDN, but not urine (u) EDN, concentration correlated with AEC and negatively correlated with prednisone dose. Both pEDN and uEDN decreased significantly following treatment of HES patients with benralizumab and EGPA patients with mepolizumab. uEDN appeared to increase with clinical relapse in both patient groups.

CONCLUSIONS

Measurement of EGP in urine is noninvasive and unaffected by cellular lysis. Although plasma and urine EDN concentrations showed a similar pattern following benralizumab and mepolizumab treatment, the lack of correlation between AEC or prednisone dose and uEDN concentrations suggests that measurement of uEDN may provide a potential biomarker of disease activity in patients with HES and EGPA.

Biomarkers and their Clinical Applications in Pediatrics

Biomarker studies are becoming increasingly interesting for many fields of medicine. The use of biomarkers in medicine is involved in detecting diseases and supporting diagnosis and treatment decisions. New research and new discoveries on the molecular basis of the disease show that there may be a number of promising new biomarkers for use in daily clinical practice. Clinical trials in children lag behind adult research both in quality and quantity. The number of biomarkers validated to optimize pediatric patient management is limited. In the pathogenesis of many diseases, it should not be extrapolated to the pediatric clinical setting, taking into account that biomarkers that are effective in adults are clearly different in children and that ontogeny directly affects disease development and therapeutic response in children. The search for ideal biomarkers or markers that can make an early and definitive diagnosis in neonatal sepsis is still ongoing. The ideal biomarker for pediatric diseases should be costeffective, noninvasive, applicable to pediatric specific diseases, and its results should correspond to age-related physiological changes. Lactate, troponin and B-type natriuretic peptide are valuable biomarkers in the evaluation and management of critically ill children with cardiac disease. Tumor markers in children are biochemical substances used in the clinical treatment of pediatric tumors and to detect the presence of cancer (regression or progression). In this chapter, current and brief information about biomarkers and their clinical applications used in the diagnosis and monitoring of pediatric diseases is presented.;

Assessing the role of eosinophil-mediated immune response markers in detecting hookworm infection: A case-control study in Kintampo, Ghana

Background and Aim

Human hookworm disease caused by Ancylostoma duodenale and Necator americanus is a serious public health problem. Hookworm infection activates eosinophil‐mediated tissue inflammatory responses, involving the production of the eosinophil‐specific chemokine (eotaxin), recruitment of eosinophils, secretion of the cationic protein, and production of antiparasite immunoglobulin E (IgE). We investigated eosinophil‐mediated immune response as markers (CCL11, eosinophil cationic protein [ECP], and IgE) for detecting hookworm infection.

Methods

This case‐control study was carried out in hookworm endemic areas within the Kintampo North Municipality.Forty hookworm‐positive subjects and 36 apparently healthy individuals were recruited as cases and controls, respectively. Stool samples were collected for hookworm detection by the Kato–Katz technique and speciation by polymerase chain reaction. Approximately, 5 ml of intravenous blood was used to obtain plasma for the immunological assays.

Results

Of eosinophil‐mediated immune response markers studied, ECP and CCL11 were significantly higher among hookworm patients compared to controls. Increasing CCL11 (β = −0.81, p = 0.015) was associated with a significant decrease hookworm intensity. However, increasing eosinophil count (β = 0.62, p = 0.027) was associated with significant increase in hookworm intensity. In receiver operator characteristics analysis, ECP could significantly detect hookworm infection with a very high area under the curve (AUC) (AUC = 0.97, p < 0.0001). At a cutoff of 39.05, ECP was the best eosinophil‐mediated immune response marker for detecting hookworm infection with a sensitivity of 97.2%, specificity of 87.8%, a positive predictive value of 89.7%, and a negative predictive value of 96.6%.

Conclusion

ECP best predicts eosinophil‐mediated immune response for detecting hookworm infection, while CCL11 and eosinophil count better predict the intensity of hookworm. Moreover, the ECP level is a good indicator of hookworm infection and intensity and may require additional investigations to augment current hookworm diagnostic techniques.

Onchocerciasis (river blindness) - more than a century of research and control

This review summarises more than a century of research on onchocerciasis, also known as river blindness, and its control. River blindness is an infection caused by the tissue filaria Onchocerca volvulus affecting the skin, subcutaneous tissue and eyes and leading to blindness in a minority of infected persons. The parasite is transmitted by its intermediate hosts Simulium spp. which breed in rivers. Featured are history and milestones in onchocerciasis research and control, state-of-the-art data on the parasite, its endobacteria Wolbachia, on the vectors, previous and current prevalence of the infection, its diagnostics, the interaction between the parasite and its host, immune responses and the pathology of onchocerciasis. Detailed information is documented on the time course of control programmes in the afflicted countries in Africa and the Americas, a long road from previous programmes to current successes in control of the transmission of this infectious disease. By development, adjustment and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas, in Uganda, in Sudan and elsewhere, followed by onchocerciasis eliminations. The current state and future perspectives for control, elimination and eradication within the next 20-30 years are described and discussed. This review contributes to a deeper comprehension of this disease by a tissue-dwelling filaria and it will be helpful in efforts to control and eliminate other filarial infections.

The Effect of Helminths on Granulocyte Activation: A Cluster-Randomized Placebo-Controlled Trial in Indonesia

BACKGROUND

Eosinophils are a prominent cell type in the host response to helminths, and some evidence suggests that neutrophils might also play a role. However, little is known about the activation status of these granulocytes during helminth infection.

METHODS

We analyzed the expression of eosinophil and neutrophil activation markers in peripheral blood by flow cytometry and measured serum levels of eosinophil granule proteins in 300 subjects residing in an area endemic for soil-transmitted helminths (STH). The data generated are on samples before and after 1 year of 3-monthly albendazole treatment.

RESULTS

Anthelmintic treatment significantly reduced the prevalence of STH. While eosinophil numbers were significantly higher in STH-infected compared to uninfected subjects and significantly decreased following albendazole treatment, there was no effect exerted by the helminths on either eosinophil nor neutrophil activation. Although at baseline eosinophil granule protein levels were not different between STH-infected and uninfected subjects, treatment significantly reduced the levels of eosinophil-derived neurotoxin (EDN) in those infected at baseline.

CONCLUSIONS

These results show that besides decreasing eosinophil numbers, anthelmintic treatment does not significantly change the activation status of eosinophils, nor of neutrophils, and the only effect seen was a reduction in circulating levels of EDN.

CLINICAL TRIALS REGISTRATION

http://www.isrctn.com/ISRCTN75636394.

An update on non-invasive urine diagnostics for human-infecting parasitic helminths: what more could be done and how?

Reliable diagnosis of human helminth infection(s) is essential for ongoing disease surveillance and disease elimination. Current WHO-recommended diagnostic assays are unreliable in low-endemic near-elimination settings and typically involve the invasive, onerous and potentially hazardous sampling of bodily fluids such as stool and blood, as well as tissue via biopsy. In contrast, diagnosis by use of non-invasive urine sampling is generally painless, more convenient and low risk. It negates the need for specialist staff, can usually be obtained immediately upon request and is better accepted by patients. In some instances, urine-based diagnostic assays have also been shown to provide a more reliable diagnosis of infection when compared to traditional methods that require alternative and more invasive bodily samples, particularly in low-endemicity settings. Given these relative benefits, we identify and review current research literature to evaluate whether non-invasive urine sampling is currently exploited to its full potential in the development of diagnostic tools for human helminthiases. Though further development, assessment and validation are needed before their routine use in control programmes, low-cost, rapid and reliable assays capable of detecting transrenal helminth-derived antigens and cell-free DNA show excellent promise for future use at the point-of-care in high-, medium- and even low-endemicity elimination settings.

The Immunomodulatory and Antimicrobial Properties of the Vertebrate Ribonuclease A Superfamily

The Ribonuclease A Superfamily is composed of cationic peptides that are secreted by immune cells and epithelial tissues. Although their physiological roles are unclear, several members of the vertebrate Ribonuclease A Superfamily demonstrate antimicrobial and immune modulation activities. The objective of this review is to provide an overview of the published literature on the Ribonuclease A Superfamily with an emphasis on each peptide’s regulation, antimicrobial properties, and immunomodulatory functions. As additional insights emerge regarding the mechanisms in which these ribonucleases eradicate invading pathogens and modulate immune function, these ribonucleases may have the potential to be developed as a novel class of therapeutics for some human diseases.

Immune Modulation by Human Secreted RNases at the Extracellular Space

The ribonuclease A superfamily is a vertebrate-specific family of proteins that encompasses eight functional members in humans. The proteins are secreted by diverse innate immune cells, from blood cells to epithelial cells and their levels in our body fluids correlate with infection and inflammation processes. Recent studies ascribe a prominent role to secretory RNases in the extracellular space. Extracellular RNases endowed with immuno-modulatory and antimicrobial properties can participate in a wide variety of host defense tasks, from performing cellular housekeeping to maintaining body fluid sterility. Their expression and secretion are induced in response to a variety of injury stimuli. The secreted proteins can target damaged cells and facilitate their removal from the focus of infection or inflammation. Following tissue damage, RNases can participate in clearing RNA from cellular debris or work as signaling molecules to regulate the host response and contribute to tissue remodeling and repair. We provide here an overall perspective on the current knowledge of human RNases’ biological properties and their role in health and disease. The review also includes a brief description of other vertebrate family members and unrelated extracellular RNases that share common mechanisms of action. A better knowledge of RNase mechanism of actions and an understanding of their physiological roles should facilitate the development of novel therapeutics.

Global Health: Urogenital Schistosomiasis in the Adolescent Girl

Urogenital schistosomiasis affects millions of women in sub-Saharan Africa. Infection by the causative organism, Schistosoma hematobium, commonly occurs during childhood and adolescence and can lead to anemia from hematuria, inflammation on the cervix which can increase risk of HIV transmission, and pelvic infection leading to infertility. Fortunately treatment is not costly, but early diagnosis is important to reduce long-term morbidity. Our objective is to review the epidemiology, pathophysiology, and diagnosis of urogenital schistosomiasis as well as treatment to improve the reproductive health of girls where this infection is endemic.

Autism spectrum disorders

Autism spectrum disorders (ASDs) are collectively the most commonly diagnosed pediatric neurodevelopmental condition. ASDs include autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), Rett syndrome and Asperger disorder. ASD is characterized by impaired communication and social interaction and may involve developmental delays and seizure disorders. Recent parent-reported diagnosis of ASD in the United States put it at higher levels (1:91) than previously thought, with its diagnosis in boys occurring 4 to 5 times more frequently than in girls (1:58).¹ CDC estimates are currently 1:110;¹ up from 1:150 in 2007.² Annual medical expenditures for those affected are generally four to six times greater than for those without ASD.¹ While twin studies demonstrate that genetics play a significant role in ASD, the impact of environment should not be underestimated, given the approximate 20-fold increase in incidence over the last 20 years.³

An extragranular compartment of blood eosinophils contains eosinophil protein X/eosinophil-derived neurotoxin (EPX/EDN)

Serum and plasma profiles of eosinophil protein X (EPX/EDN) and those of other eosinophil proteins differ in various conditions, suggesting a different mobilisation from storage granules. This work studied the subcellular localisation of EPX/EDN in non-primed and in vivo primed blood eosinophils from healthy and allergic subjects, during and out of the pollen season. Primed eosinophils contain easily mobilisable secretory proteins. By fractionation on sucrose density gradients, EPX/EDN localised in the specific granules as well as in a cytoplasmic extra-granular compartment of low equilibrium density that partially overlapped with vesicular structures, cytosolic proteins and plasma membranes. This compartment was clearly separate from the low density peak of ECP that increases during the pollen season. There were no significant differences in the amounts of EPX/EDN present in the low density peak of healthy and allergic subjects. Immuno-gold labelling electron microscopy showed EPX/EDN in specific granules, cytoplasm and associated to plasma membranes. In conclusion, substantial amounts of EPX/EDN localise in an extra-granular, low equilibrium density compartment of human eosinophils.

Eosinophilic activity and bronchial hyperresponsiveness within an asthmatic paediatric population

BACKGROUND

Our study aims to assess the importance of serum eosinophil cationic protein (ECP) levels as a non-invasive marker of bronchial hyperresponsiveness (BHR) in children with asthma, and may predict objectively the asthmatic severity and sensitivities.

METHODS

This study, which was carried out on 75 asthmatic patients from a paediatric population (average age: nine years old, sex-ratio M/F: 1.64), is based on both interrogation conducted by the clinician and biological explorations, essentially serological testing of ECP and eosinophilia determination, as well as the measurement of serological IgE amounts.

RESULTS

The analysis of the questionnaires and the biological results allowed us to evaluate the clinico-biological relations within this population. ECP, more than eosinophilia, proves to be a relevant marker of asthma severity (p<0.05) and sensitivities within this given population (r=0.65).

CONCLUSION

We were able to show that the evaluation of the serological levels of ECP seems to be a good biological marker of asthma.

Analysing the eosinophil cationic protein--a clue to the function of the eosinophil granulocyte

Eosinophil granulocytes reside in respiratory mucosa including lungs, in the gastro-intestinal tract, and in lymphocyte associated organs, the thymus, lymph nodes and the spleen. In parasitic infections, atopic diseases such as atopic dermatitis and asthma, the numbers of the circulating eosinophils are frequently elevated. In conditions such as Hypereosinophilic Syndrome (HES) circulating eosinophil levels are even further raised. Although, eosinophils were identified more than hundred years ago, their roles in homeostasis and in disease still remain unclear. The most prominent feature of the eosinophils are their large secondary granules, each containing four basic proteins, the best known being the eosinophil cationic protein (ECP). This protein has been developed as a marker for eosinophilic disease and quantified in biological fluids including serum, bronchoalveolar lavage and nasal secretions. Elevated ECP levels are found in T helper lymphocyte type 2 (atopic) diseases such as allergic asthma and allergic rhinitis but also occasionally in other diseases such as bacterial sinusitis. ECP is a ribonuclease which has been attributed with cytotoxic, neurotoxic, fibrosis promoting and immune-regulatory functions. ECP regulates mucosal and immune cells and may directly act against helminth, bacterial and viral infections. The levels of ECP measured in disease in combination with the catalogue of known functions of the protein and its polymorphisms presented here will build a foundation for further speculations of the role of ECP, and ultimately the role of the eosinophil.

Dietetic effects of oral intervention with mare's milk on the Severity Scoring of Atopic Dermatitis, on faecal microbiota and on immunological parameters in patients with atopic dermatitis

In a double-blind, placebo-controlled crossover trial, 23 patients consumed 250 ml mare's milk or placebo for 16 weeks. The aim was to examine the effects of mare's milk on the characteristics of atopic dermatitis (AD), on faecal microbiota and on clinical and immunological parameters. The intensity of AD was examined using the Severity Scoring of Atopic Dermatitis (SCORAD) index. During the mare's milk period, the mean SCORAD value of patients (n=23; 17 females, 6 males) decreased from 30.1 to 25.3 after 12 weeks (P<0.05) and to 26.7 after 16 weeks (P<0.1). In a subgroup (n=7) the SCORAD index and especially the pruritus decreased by 30% through the mare's milk period (P<0.01). In this subgroup, the faecal bifidobacteria increased during the mare's milk period from 4.6% to 11.9% of eubacteria (P<0.05). The immunological parameters, except C-reactive protein, were unchanged.

Relationships between cotinine, lower respiratory tract infection, and eosinophil cationic protein in children

INTRODUCTION

The aim of this study was to investigate the effect of passive smoking on urine eosinophil cationic protein (u-ECP) in children with lower respiratory tract infections (LRTI).

METHOD

This was a case-control study. The study cohort consisted of 150 children with LRTI (case group) and 150 healthy children (control), all from a urban setting. The statistical parameters were: a minimum of 139 children for a 95% confidence interval (95% CI), 80% power, and a possible exposure prevalence of 50%. The u-cotinine and u-ECP levels were measured by radioimmunoassay and fluoroimmunoassay methods, respectively. Data were analyzed by the McNemar chi-square test, t-test, and Pearson correlation.

RESULTS

When the generally accepted cut-off level of 30 ng/mg urinary cotinine/creatinine was applied, 87.3% of the children with LRTI and 84.7% of healthy children were passive smokers. Using a cut-off level of 60 ng/mg, passive smoking increased the prevalence of LRTI by 4.7-fold (p=0.000). The mean u-ECP values were significantly higher in the case group than in the healthy control group (p=0.018). A positive association was found between u-cotinine and u-ECP values in children with LRTI (p=0.034).

CONCLUSION

The results of this study indicate that passive smoking may play an important role in the development of respiratory infections and can cause airway inflammation in children with existing LRTI.

The effect of an indirect anthelmintic treatment on parasites and breeding success of free-living pheasantsPhasianus colchicus

In Great Britain free-living common pheasantsPhasianus colchicusare often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species includingHeterakis gallinarum,Capillariaspp. andSyngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasiteH. gallinarumwere significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.

Eosinophil cationic protein, specific IgE and IgG4 in human toxocariasis

Among 67 French patients presenting a toxocaral infection, various demographic, environmental, clinical and laboratory parameters (blood eosinophil count, eosinophil cationic protein (ECP), serum total IgE, specific IgE against common inhalant allergens, specific IgE and IgG4 againstToxocaraexcretory-secretory antigens) were investigated. Correlation studies and logistic regression analyses were conducted, testing elevated levels of ECP, specific anti-ToxocaraIgE or IgG4 as outcome variables An elevated ECP level was significantly associated with both cough and rhinitis, a high level of specific anti-ToxocaraIgE with itchy rashes and possible atopic status, and an increase of specific anti-ToxocaraIgG4 with rural residence.

Eosinophils and atopic dermatitis

In spite of the progress regarding the description of immunological phenomena associated with atopic dermatitis (AD), the pathogenesis of this disease still remains unclear. The presence of eosinophils in the inflammatory infiltrate of AD has long been established. Eosinophil numbers as well as eosinophil granule protein levels in peripheral blood are elevated in most AD patients and appear to correlate with disease activity. Moreover, eosinophil granule proteins, which possess cytotoxic activity, are deposited in the skin lesions. These observations indicate a role of eosinophils in the pathogenesis of AD. Furthermore, AD is associated with increased production of T helper 2 cytokines including interleukin (IL)-5, which specifically acts on eosinophils, resulting in accelerated eosinophilopoiesis, chemotaxis, cell activation, and delayed apoptosis. Therefore, IL-5 is an interesting target for experimental therapy in this inflammatory disorder of the skin. Such studies might result in new insights into the pathogenetic role of eosinophils in AD.

Eosinophil degranulation during pregnancy and after delivery by cesarean section

BACKGROUND

The physiological roles of eosinophils that accumulate in the uterus during pregnancy and of uterus-dwelling mast cells remain unknown. In the present study, we investigated the degranulation of eosinophils and mast cells within the normal course of pregnancy and after delivery by measuring the urinary concentrations of eosinophil-derived neurotoxin (EDN) and N-methylhistamine.

METHODS

Spot urine samples from 65 pregnant women and 15 nonpregnant, age-matched women were examined. Urinary EDN and N-methylhistamine concentrations were measured by radioimmunoassay and standardized with urinary creatinine concentration.

RESULTS

A significant increase in the urinary EDN concentration was observed until the second trimester in the normal pregnancies. The elevated urinary EDN levels decreased after the onset of labor in the third trimester and normalized within 1 month after normal vaginal delivery. In women who underwent a cesarean section, the urinary EDN concentration was significantly higher for up to 1 month after delivery, compared to that in women who underwent a vaginal delivery. In contrast, the urinary N-methylhistamine concentration did not change until the second trimester and was significantly decreased during the third trimester. No significant correlation between the peripheral blood eosinophil count and the urinary EDN concentration was observed in these subjects.

CONCLUSIONS

Eosinophils appear to play a role in the progression of pregnancy and recovery after a cesarean section through the degranulation of eosinophils. In addition, mast cell degranulation does not appear to be related to the contraction of uterine smooth muscle during labor.

Localized eosinophil degranulation mediates disease in tropical pulmonary eosinophilia

To explore the mechanisms underlying the eosinophil-mediated inflammation of tropical pulmonary eosinophilia (TPE), bronchoalveolar lavage (BAL) fluid, serum, and supernatants from pulmonary and blood leukocytes (WBC) from patients with acute TPE (n = 6) were compared with those obtained from healthy uninfected individuals (n = 4) and from patients with asthma (n = 4) or elephantiasis (n = 5). Although there were no significant differences in the levels of interleukin-4 (IL-4), IL-5, IL-13, eotaxin, granulocyte-macrophage colony-stimulating factor, RANTES, or eosinophil cationic protein, there was a marked increase in eosinophil-derived neurotoxin (EDN) both systemically and in the lungs of individuals with TPE compared to each of the control groups (P < 0.02). Moreover, there was a compartmentalization of this response, with EDN levels being higher in the BAL fluid than in the serum (P < 0.02). Supernatants from WBC from either whole blood or BAL cells were examined for chemokines, cytokines, eosinophil degranulation products, and arachidonic acid metabolites. Of the many mediators examined-particularly those associated with eosinophil trafficking-only EDN (in BAL fluid and WBC) and MIP-1alpha (in WBC) levels were higher for TPE patients than for the non-TPE control groups (P < 0.02). These data suggest it is the eosinophilic granular protein EDN, an RNase capable of damaging the lung epithelium, that plays the most important role in the pathogenesis of TPE.